Method and apparatus for installing an underwater well



W. L.- TODD May 14, 1968 METHOD AND APPARATUS FOR INSTALLING AN UNDERWATER WELL 13 Shee ts-Sheet 1 Filed Nov.

mvsmon WILLIAM L. TODD BY W i ATTORNEY May 14, 1968 w. L. TODD 3,332,921

METHOD AND APPARATUS FOR INSTALLING AN UNDERWATER WELL Filed Nov. 13, 1964 13 Sheets-Sheet 3 'FILGK \2 INVENTOR WILLIAM L. "r000 32 ATTORNEY May 14, 1968 w. L. TODD 3,382,921

METHOD AND APPARATUS FOR INSTALLING AN UNDERWATER WELL Filed Nov. 1 5, 1964 13 Sheets-Sheet 4 INVENTOR WILLIAM L. TODD ATTORNEY May 14, was w. L. TODD 3,38

METHOD AND APPARATUS FOR INSTALLING AN UNDERWATER WELL Filed Nov. 13, 1964 13 Sheets-Sheet 5 i 228 22s A 1 230 226 i Q 224 i 224 viESS J INVENTOR WILLIAM 1.. 1000 ATTORNEY W. L. TODD May 14, 1968 METHOD AND APPARATUS FOR INSTALLING AN UNDERWATER WELL l3 Sheets-Sheet 6 Filed Nov. 13, 1964 y 14, 1958 w. L. TODD 3,382,921

METHOD AND APPARATUS FOR INSTALLING AN UNDERWATER WELL Filed NOV. 15, 1964 13 Sheets-Sheet '7 INVENTOR WILLIAM L. TODD BY W /W ZZJ.

ATTORNEY W. L. TODD May 14, 1968 METHOD AND APPARATUS FOR INSTALLING AN UNDERWATER WELL 13 Sheets-Sheet 8 Filed Nov. 13, 1964 ATTORNEY w. 1.. TODD 3,382,921

METHOD AND APPARATUS FOR INSTALLING AN UNDERWATER WELL May 14, 1968 13 Sheets-Sheet 9 Filed Nov. 13, 1964 INVENTOR WILLIAM L. TODD ATTORNEY y 14, 1968 w. L. TODD 3,382,921

METHOD AND APPARATUS FOR INSTALLING AN UNDERWATER WELL Filed Nov. 13, 1964 13 Sheets-Sheet 10 INVENTOR WILLIAM L. TODD BY ee W' ATTORNEY W. L. TODD May 14, 1968 METHOD AND APPARATUS FOR INSTALLING AN UNDERWATER WELL 13 Sheets-Sheet 1 1 Filed Nov.

0 T wL mm M lw W Y E N R O T A May 14, 1968 w. L. TODD 3,

METHOD AND APPARATUS FOR INSTALLING AN UNDERWATER WELL Filed Nov. 15, 1964 13 Sheets-Sheet 12 INVENTOR WILLIAM L. TODD BY mw/W ZL.

ATTORNEY May 14, W. L. TODD METHOD AND APPARATUS FOR INSTALLING AN UNDERWATER WELL Filed Nov. 1 5, 1964 13 Sheets-Sheet 15 INVENTOR I WILLIAM L. TODD ATTORNEY United States Patent Oflice 3,382,921 Patented May 14, 1968 3,382,921 METHOD AND APPARATUS FOR INSTALLING AN UNDERWATER WELL William L. Todd, Pasadena, Calif., assignor to FMC Corporation, San Jose, Calif., a corporation of Delaware Filed Nov. 13, 1964, Ser. No. 411,042 11 Claims. (Cl. 16688) ABSTRACT OF THE DISCLOSURE A Well completion apparatus specially adapted for remote installation in an underwater well, including a casing hanger with a body having passages for conducting fluid past the hanger and a valve sleeve slidably mounted on the body for controlling the fluid flow through the pas sages, a tubing hanger that seats and locks in the casing hanger and yet is readily withdrawable therefrom for pulling the suspended tubing, and a method for completing an underwater well using the aforementioned apparatus.

During cementing, acidizing or other operations requiring circulation through a well it is necessary either to lift the casing hanger from its seat in the casing head to open a return fiow path to the surface conductor or to use a casing head having a side outlet beneath the seat and a surface conductor return to the drilling barge or platform. In the case of a submerged well and a drill rig on a floating barge it is often impractical to lift the casing hanger because the casing string rises and falls with the barge and damage to the wellhead apparatus can easily occur. At the very least, lifting the casing hanger to obtain a return flow path to the barge is an inconvenient operation which it is desirable to eliminate. If the well is a low pressure well, there may not be any need for a side outlet casing head to determine the casing annulus pressure, in which case the side outlet represents an unnecessary extra cost in that a diver must remove its connections and insert an outlet plug. While remotely operable apparatus has been provided in the past for lifting the casing hanger at the Wellhead, such apparatus increases cost because it is not a part of the completed wellhead, besides involving the step of lifting the casing hanger. The apparatus of the present invention eliminates both the lifting of the casing hanger and a side outlet casing head, circulation into and out of the well being accomplished through a permanently installed casing hanger.

The installation of underwater wellhead fixtures is preferably accomplished by manipulation from the drilling barge so as to minimize the services of divers. Also, it is in the interests of safety and low cost to be able to install the flow line of the well from the drilling barge while the blowout preventers are in place. The method steps of the present invention provide a simplified underwater wellhead installation procedure which is of particular utility with low pressure wells in Water that is within the range of a diver.

One of the objects of the present invention is to provide an improved method of installing underwater well apparatus.

Another object is to provide an improved method of installation for the flow line of an underwater well.

A further object of the invention is to provide an underwater wellhead installation method which minimizes the services of a diver.

Another object is to provide an improved method for maintaining a submerged well under pressure control while the production tubing is installed.

Another object is to provide an improved method for installing a flexible flow line to underwater wellhead structure through the blowout preventers of the drill rig on a drilling barge.

Another object is to provide an improved easing hanger.

Another object of the present invention is to provide a casing hanger having a port which extends through the hanger and is capable of being opened or shut from a remote location.

A further object is to provide a casing hanger and associated sleeve valve which controls a fluid conducting passage through the body of the hanger, so constructed and arranged that rotating a landing tool for installing the hanger will simultaneously close the valve and disengage the landing tool from the hanger.

Another object is to provide a remotely operable releasable coupling for members of a well apparatus.

Another object is to provide a tubing hanger having integral, remotely operable locking means for receiving and releasably securing fiow apparatus for producing the well.

Other objects and advantages of the present invention will become apparent from the following specification and from the accompanying drawings, wherein:

FIGURE 1 is a diametral section through well apparatus of the present invention including a casing hanger and landing tool used to install the hanger.

FIGURE 1A is a transverse section through the landing tool and the casing hanger shown in FIGURE 1, and is taken along lines 1A1A thereon.

FIGURE 2 is a section similar to FIGURE 1 and particularly illustrates the casing hanger landed in a supporting casing head, but not locked therein.

FIGURE 3 is a diametral section similar to FIGURE 2, but along a different section plane, and shows the casing hanger in a locked position and the landing tool partially removed therefrom.

FIGURES 4 and 5 are transverse sections taken along the respective lines 4-4 and 55 on FIGURE 1.

FIGURE 6 is a transverse section along lines 6-6 on FIGURE 2.

FIGURE 7 is a transverse section along lines 77 on FIGURE 1.

FIGURE 8 is a diametral section through the tubing hanger of the present invention and illustrates the tubing hanger being installed by a landing tool in the upper portion of the casing hanger shown in FIGURES 1-3.

FIGURE 9 is a section similar to FIGURE 8 but shows the tubing hanger in a landed and locked position.

FIGURE 10 is an enlarged transverse section along lines Iii-10 on FIGURE 8.

FIGURES 11 and 12 are enlarged transverse sections along the respective lines 11-11 on FIGURE 9 and 12--12 on FIGURE 8.

FIGURES 13 and 14 are operational views similar to FIGURES 8 and 9 but illustrating the use of an unlocking and lifting tool for unlocking and removing the tubing hanger from the casing hanger.

FIGURE 15 is a schematic elevation, partially broken away, illustrating the initial method step of the present invention, the installation of a primary base unit at the time the drill string and bit is run in.

FIGURE 16 is a schematic fragmentary elevation showing the casing guide and surface casing being lowered toward the primary base unit for installation in the borehole.

FIGURE 17 is a schematic fragmentary elevation, partially broken away, showing detachment of the casing guide and the lowering of a wellhead assembly including a drilling valve, casing head and main guide system.

FIGURE 18 is a schematic fragmentary elevation, partially broken away and in section, particularly illustrating the landing of the casing hanger and the completion of the cementing operation.

FIGURE 19 is an elevation similar to FIGURE 18, partially broken away and in section, and depicts the installation of the tubing string, tubing hanger and a flexible flow line communicating with the drilling barge.

FIGURE 20 is a schematic fragmentary elevation of the completed wellhead fixture installation before the flexible flow line leading to the barge is lowered to the bottom.

FIGURES 21, 22 and 23 are schematic fragmentary elevations respectively illustrating the plugging of the upper end of the flow line, the installation of a valve and a valve removal tool to remove the plug, and the opening of the valve after the valve removal tool is removed for discharging the production fiow to clean up the well.

FIGURE 24 is a schematic elevation of the wellhead apparatus and is helpful in describing the final step of coupling the flexible flow line to a conductor lying on the bottom.

Apparatus The underwater well apparatus 24 (FIGS. 1 and 2) of the present invention includes a tubular mandrel 22 which is positioned within an annular casing hanger 24, a valve sleeve 26 that is slidably mounted on the mandrel 22 and the body 2 and a tubing hanger 28 (FIG. 8) which is adapted to be seated in the mandrel to support the production tubing of the completed well. As will subsequently be described in detail, the casing hanger 24, the tubing hanger 28 and the sleeve 26 are particularly adapted to be installed in a submerged wellhead apparatus from a remote point such as a floating drilling barge B (FIG. Further, the casing hanger and tubing hanger are interrelated in that the mandrel 22, serves as a part of the casing hanger assembly and also functions as a tubing head for supporting the tubing hanger 28.

Casing hanger More specifically, the mandrel 22 (FIG. 1) is provided with external threads 29 on its lower end portion which are screwed into mating threads in a coupling sleeve 30. The coupling sleeve is in turn threaded onto a depending intermediate casing or oil string 32 that is to be run into the borehole of an underwater well. The upper end portion of the mandrel 22 is provided with a counterbore 33 that includes an annular locking groove 34 and an inclined annular support shoulder 36 that are respectively adapted to lock and to support the tubing hanger 28 (FIG. 8) within the mandrel 22 after the mandrel and its attached casing hanger 24 and sleeve 26 have been installed at the wellhead.

During such installation, the mandrel 22 (FIG. 1) is suspended from a tubular landing tool 38 which is secured to the bottom end, not shown, of a running string of pipe 296 (FIG. 18) that extends to the drilling barge or ship. The landing tool 38 (FIG. 1) and the mandrel 22 are releasably interconnected by means of interengaging lefthand threads at 46 and 41, respectively, whereby subsequent clockwise rotation of the landing tool 3%, after the casing hanger 24 is supported by and locked to a casing head 43 (FIG. 2), will cause the tool 38 to unscrew from the mandrel 22. In the running position of the landing tool and mandrel, illustrated in FIGURE 1, conventional O-rings 42, which are mounted in external annular grooves in the landing tool, effect a fluid seal between the tool and mandrel.

The upper end portion of the valve sleeve 26 (FIGS. 1 and 1A) is provided with inwardly facing lugs and grooves 44 and 45, respectively, which are intermeshed with lugs and grooves 46 and 47, respectively, that are formed on the tool 33. Accordingly, when the landing tool is rotated by means of the running string of pipe 296 to which the tool is secured, the valve sleeve 26 rotates with the land- 4 ing tool. However, while the sleeve can be positively rotated by the landing tool, the lug and groove interengagemerit of the sleeve and landing tool does not prohibit relative longitudinal movement therebetween.

Under certain operating conditions later described, the valve sleeve 26 is lowered relative to the mandrel 22 until an inner radial abutment 48 of the sleeve engages the upper surface of a stop ring 56 which projects from an exterior groove in the Wall of the mandrel. The stop ring 5% limits axial movement only of the sleeve 26.

Internal right-hand threads 52 are formed in the wall of the sleeve 26 between the abutment wall 48 and the lower end 54 of the sleeve. Threads 52 are engaged with external threads 56 that are formed on a nut 58 which has an inturned upper flange end 60. The flange of the nut is provided with a cylindrical bore and is vertically movable on the mandrel 22 between a lower stop ring 62, which is mounted in a corresponding groove in the mandrel, and an upper abutment ledge 64 which is formed by a stepped portion of the outer wall of the mandrel. The nut 58 engages the stop ring 62 until the entire casing hanger is supported in its operative position within the casing head 43 (FIG. 2).

The casing hanger 24 (FIG. 1) is provided with a body 65 having an exteriorly threaded upper end portion 66 which is engaged with corresponding internal threads on the nut 58. During assembly of the hanger body and nut, the nut is thus securely locked to the casing hanger body. It will be noted that an annular recess 68 in the inner surface of the casing hanger body adjacent the nut 58 permits the hanger to move upward relative to the mandrel 22 without initial interference with the stop ring 62, and far enough so that the nut flange 69 can engage the ledge 64 before the ring 62 can engage the bottom end wall of the recess 68.

Two vertical slots 70 (FIGS. 1 and 7) are formed in the exterior surface of the mandrel 22 below the stop ring 62, and the slots are positioned, upon assembly of the casing hanger 24 on the mandrel, opposite matching radial apertures 72 in the hanger. An anti-rotation pin 74 is then driven inward through each aperture 72 until its inner end portion lies within the slot 70 so as to prevent relative rotation between the hanger 24 and the mandrel 22. Since the slots 70 are vertically elongate, however, limited relative axial movement between the hanger body and the mandrel is unimpeded by the pins 74 until the pins strike the end walls of their respective slots.

As is most clearly shown in FIGURE 7, two shear pins 76 are secured in radial apertures 78 of the hanger 24 and lie in the same plane as the anti-rotation pins 74, but are angularly displaced therefrom. Until the casing hanger 24- is completely installed within the casing head 43 (FIG. 2), the shear pins 76 maintain the relative axial positions of the mandrel 22 and the casing hanger 24. Further, the assembled position of the sleeve 26 on the mandrel 22, the nut 58 and the casing hanger 24 is such that the lower end 54 of the sleeve projects just below two O-rings 80 that are mounted in annular grooves on the hanger body and effect a fluid-tight seal between the body and the sleeve.

Immediately below the O-rings 80 are four radial ports 32 (FIGS. 1 and 7) which each communicate with and form a part of a vertical passage 84 that extends longitudinally through the wall of the casing hanger body 65. The ports and pasages 82 and 84 are indicated by phantom lines in FIGURE 1 because they are removed from the section plane. Each passage 84 terminates at the frusto-conical lower end 86 of the casing hanger body.

A pair of O-rings 88 are mounted in annular grooves in the casing hanger body 65 below the radial ports 82 and are adapted to effect a fiuid tight seal between the hanger body and the sleeve 26 after certain operational steps have been carried out subsequent to the installation of the casing hanger in the casing head 43. These steps include, first, the severing of the shear pins 76 (FIG. 7) and,

second, rotation of the landing tool 38 (FIG. 1) to elfect a lowering of the sleeve 26 (FIG. 1) until its abutment 48 seats upon the stop ring 50. When these steps are accomplished, the lower end 54 of the sleeve 26 projects below the lowermost O-ring 88 (FIG. 3) and thus blocks off the ports 82 and prevents any fluid circulation through their passages 84.

Four lockings lugs 90 (FIGS. 1 and 5) are slidably mounted in radial apertures of the casing hanger 24, each lug having an inclined inner camming surface 94 which in the illustrated FIGURE 1 running position of the casing hanger is engaged with an annular beveled camming ledge 96 on the exterior of the mandrel 22. So positioned, the outer arcuate ends 98 of the locking lugs 90 are flush with the exterior surface of the casing hanger body 65.

The inner end portions of the locking lugs 91) (FIG. 5) are circumferentially wider than the body of the lugs so as to obtain the greatest practicable amount of engagement with the camming ledge 96 (FIG. 1). For this reason, the inner ends of the radial apertures in which the lugs are mounted each merge with an individual arcuate recess 100 (FIGS. 1 and 5) which is as high as the lug to provide clearance sufiicient to accommodate the subsequent outward projection of the lug by the camming ledge 96. The lugs 90 are projected outward when the previously mentioned operational step of severing the shear pins 76 is carried out during installation of the casing hanger in the casing head 43 and the consequent lowering of the mandrel 22 within the casing hanger 24.

The bottom, inner edge of each recess 100 (FIG. 1) merges with an annular ledge 164 which diverges upwardly from the bore of the casing hanger body 65, the ledge 104 subsequently providing a support surface for the camming ledge 96 of the mandrel 22 after the shear pins 76 (FIG. 7) have been severed. A pair of O-rings 108 (FIG. 1), which are mounted in the bore of the casing hanger body, seal between the body and the mandrel 22.

The marginal edge portion of the frusto-conical lower end 86 of the casing hanger body 65 has an annular recess 111) in which is mounted both a resilient sealing or packing ring 112, and a rigid junk ring 114 that abuts the sealing ring 112 and is retained in place by a snap ring 116. A beveled lower edge 118 of the junk ring 114 is adapted to engage a mating beveled edge 119 (FIG. 2) in the casing head 43 upon installation of the casing hanger 24 whereby the sealing ring 112 expands laterally into sealing engagement with an adjacent wall 121 of the casing head.

It should again be noted (FIGS. 2 and 3) that clockwise rotation of the landing tool 38 will lower the valve sleeve 26 relative to both the mandrel 22 and the casing hanger 24 until the ports 82 are blocked off and will simultaneously effect disengagement of the landing tool from the mandrel. Also, when the casing hanger 24 is supported in the casing head and the landing tool 38 is removed, the weight of the depending casing string 32 pulls downward on the mandrel with sufficient force to seve the shear pins 76 (FIG. 7), whereby the mandrel drops into engagement with the nut flange 60 and in so doing, the camming ledge 96 on the mandrel cams out the locking lugs 90.

The casing head 43 (FIG. 2) is cemented at 122 in the borehole 124 and is attached to the upper end of a depending string of threaded surface casing 126. The flanged lower end portion 128 of an annular drilling valve 130 (FIG. 17) is clamped to the upper flange 132 of the casing head 43 by a split C-section clamp 134. A junk ring 136 is mounted beneath a packing ring 138 on a reduced diameter lower end portion of the valve 131). During installation of the valve, a beveled lower corner of the junk ring seats on a ledge 140 in the casing head before the flanges 128 and 132 abut. The packing ring 138 is thus expanded laterally into sealing engagement with the valve 136 and the casing head 43.

Because pressure indication for the casing annulus 137 between the casing strings 32 and 126 may not be necessary in a low pressure well, in which the present apparatus is particularly useful, side outlet annulus pressure connections in the casing head 43 can be dispensed with. Further, side outlet flow connections for fluid circulation through the well are eliminated since the flow passages 84 communicate with the annular passage 137 between the inner and outer casing strings below the hanger body 24, and with an annular passage 142 between the wall of the valve 1311 and the sleeve 26.

A counterpart to the annular passage 142 above the drilling valve is formed between a surface conductor 294 (FIG. 18) and the running string 296. The surface conductor 294 is connected to a ball valve 274 that is carried by the drilling valve 130; the casing annulus 137 (FIG. 2) can thus communicate with the drilling barge when the ports 82 are not blocked by the sleeve 26.

The installation of the casing hanger 24 and associated apparatus is briefly summarized at this point. When the casing hanger 24 is initially landed in the casing head 43, the beveled lower edge 118 of the junk ring 114 engages the mating beveled edge 119 in the lower portion of the casing head, whereby the sealing ring 112 is transversely expanded into tight fluid-sealing engagement with the easing hanger body 65 and the wall 121 of the casing head 43. As the running string of casing 296 (FIG. 18) supporting the landing tool 38 is lowered farther, the weight of the casing string 32 pulling the mandrel 22 downward causes the shear pins 76 (FIG. 7) to be severed.

The mandrel 22 (FIG. 2) is thus lowered within the immobilized casing hanger 24 until its abutment ledge 64 rests upon the flange 60 of the nut 58. Meanwhile, the camming ledge 96 (FIGS. 2 and 6) on the mandrel cams the locking lugs 90 outward into an interior annular locking groove 146 and comes to rest against the ledge 184 in the casing hanger body 65. With the foregoing parts thus installed, cementing operations between the intermediate casing string 32 and the bottom portion of its borehole can be carried out.

The cement is run down the casing string 32 (FIG. 2) and the circulation return, as the cement displaces the drilling mud, is upward through the annular space 137, through the circulation ports 84 and 82, through the annular space 142 between the valve sleeve 26 and the valve 130, and thence to the drilling barge. When the cementing operation is finished, the landing string of casing 296 carrying the landing tool 38 is rotated at the barge in a direction to cause the left-hand threads 46 and 41 of the landing tool 38 and the mandrel 22 to move toward disengaged positions. At the same time, the righthand threads 52 and 56 of the valve sleeve 26 and the nut 58, respectively, move the sleeve downward over the casing hanger body 65 while the lugs 46 of the landing tool 38 remain engaged with the grooves 44 in the sleeve. The landing tool 38 thereby rotates and lowers the sleeve 26 at the time time it is being unthreaded from the mandrel 38.

Just before the landing tool 38 (FIG. 3) reaches its illustrated disengaged position, the bottom end 54 of the sleeve 26 has been projected below the lateral ports 82 in the casing hanger body 65. The casing annulus 137 is thus isolated from the annular fiow space 142, Installation of the production tubing string and the tubing hanger 28 (FIG. 8) can proceed after the landing tool and its running string of pipe are lifted onto the drilling barge.

Tubing hanger The tubing hanger 28 (FIG. 8) includes a tubular mandrel 150 having exterior threads 152 on its upper end portion, and interior threads 154 in its lower end portion which connect to a depending production tubing string 155. Intermediate its ends, the mandrel is provided with an integral outwardly projecting flange 156 which has an upper end 158, a lower end 160, and an inclined peripheral camming surface 162. The lower portion of the mandrel 150 is slidable within a bore 164 in the lower end '7? wall 165 of a hollow, cylindrical tubing hanger body 166 of the tubing hanger 28. O-rings 168 are mounted in that portion of the wall 165 which defines the bore 164, and provide a fluid-tight seal between the mandrel and the body but permit relative axial movement between the mandrel and body. Other O-rings 167 are conventionally mounted in grooves in the lower portion of the hanger body 166 and are adapted to seal against the inner wall of the mandrel 22 when the tubing hanger is installed therein.

Flange 156 is slidable within the hanger body 166 be tween an uppermost position in which its upper end 153 abuts the underside of a nut 1'70 and a lowermost position wherein its lower end 160 rests upon the upper surface f the wall 165. Four equally spaced locking lugs 172 (FIGS. 8 and 10) are slidably mounted within corresponding radial apertures 174 in the wall of the body 166 and have inner arcuate end surfaces complementary to the camming surface 162 on the flange 156. The arcuate outer ends or" the locking lugs 172 are flush with the exterior surface of the hanger body 166. The inner end of each lug 172 is wider than the body of the lug; for this reason a circumferential recess 176 (FIG. 16) is provided in the adjacent portion of the tubing hanger body 166 so as to accommodate the wide inner ends of the lugs when the cumming surface 162 subsequently projects the lugs outward into the locking groove or recess 34 in the mandrel 22.

The nut 17% (FIG. 8) is provided with exterior screw threads 178 that are engaged with corresponding internal threads 1% in the upper end portion of the tubing hanger body 166 and has a cylindrical bore 132 through which passes the upper portion of the mandrel 166. A counterbored upper portion of the nut 1'74. is threaded at 184 to receive the corresponding screw threads 185 on a iople 186 that is integrally formed on the underside of a circular flange portion or end wall 183 of a collet 199.

The collet 199 (FlGS. 8 and 12) is provided with an opposed pair of shear pins 192 which lie in diametrically opposite apertures 194 that are formed in the flange 138. The inner end portions of the shear pins 192 are positioned within blind mating recesses formed in the outer surface of the mandrel 159. in the same plane as the shear pins 192 (FIG. 12) and normal thereto are two opposed anti'rotation pins 1%. The pins 1% are locked in apertures 1%8 of the flange 188 and their inner end portions are positioned within vertical slots 290 that are formed in the outer surface of the mandrel 150. The slots 20% are sufliciently long to permit the flange 156 to seat upon the wall 165 when the shear pins 192 are severed. The shear pins 192 are thus severed when the weight of the production tubing string 155, which depends from the mandrel 150, causes the mandrel to move downward in the tubing hanger body 166 after the tubing hanger is landed in the mandrel 22.

Installation of the tubing hanger 28 to its suppo ted FTGURE 8 position within the mandrel 22 is effected in much the same manner as the installation of the casing hanger 24 within the casing head 43, ie, the tubing hanger and other associated structure depend from a running string of pipe 296 (FIG. 19) which lowers the hanger until its beveled lower support surface 202 (FIG. 8) rests upon and is supported by the support shoulder 36. Continued downward movement of the running string of pipe thus transfers the support of the production tubing string 155 directly to the immobilized tubing hanger when suihcient weight is transferred to the mandrel 156 to sever the shear pins 192 and the mandrel moves to its lowermost position.

The flange portion 183 of the collet is provided with a plurality of upstanding, integrally formed and resiliently flexible collet or locking fingers 2% that are preferably equally spaced about the circumferential edge of the flange. Each finger is provided with a sloping inner cumming surface 210 and a lateral abutment ledge 212 which, when the finger is unstressed and unflexed, projects inwardly beyond the inner surface of a resilient lower portion 214. The collet fingers 263 can be flexed outward, as shown in FIGURE 8, when a collar 2m, that is part of a normally open, preferably ball-type, master valve 218, descends into contact with the camming surfaces 23%. The fingers 263 are thus cammed outward, and when the collar attains its FIGURE 9 seated position upon the flange 188, the fingers 208 are released and spring inward so that the abutment ledges 212 overlie the upper end or shoulder of the collar and prevent upward movement thereof.

The master valve 218 includes a hexagon socket valve actuator 222 for opening and closing the valve and an exteriorly threaded portion 224 which projects radially outward from the upper end portion of the valve 218 and is provided with lefthand threads. Further, the upper end portion of the valve 213 is provided with internal threads, not shown, which are adapted to receive a threaded male portion, also not shown, of a hose fittting coupling 226. Coupling 226 is fitted to a flexible flow line 228 that ultimately is used to produce the well. The ball valve 218 is installed in an open condition so that well fluid can flow into the flow-line 228.

At this stage of installation of the tubing hanger 166, the flow line 223 (FIG. 8) exiends to the drilling barge through the running string of casing 296 (FIG. 19) and through conventional blowout preventers of the drilling rig on the barge B. The lower end of the casing 296 is threaded into the upper end portion of an adapter sleeve 230 which is in turn threaded onto the threaded portion 224 of the valve 218. Thus, by providing valve means on the upper end of the flow line 228 at the drilling barge, the well is under complete control at the barge when the tubing hanger 28 is locked in the mandrel 22.

Locking of the tubing hanger 28 is automatically effected in the manner already described when the mandrel 156 drops to its FIGURE 9 position after weight of the tubing string 155 is transferred to the tubing hanger body 166 due to severance of the shear pins 192. The camming surface 162 of the mandrel 15G accordingly cams the locking lugs 172 outwardly into the annular locking groove 34 which lies opposite the lugs 172 when the tubing hanger body 166 is seated within the mandrel 22. The upper circumferential portion of the flange 156. which has the lug cumming surface 162, is now positioned behind the locking lugs 172 whereby the tubing hanger body 166 is securely locked in the mandrel 150, and the master valve 218 and mandrel are securely locked to the mandrel by the collet fingers 208.

The weight of the production tubing string 155 and the frictional interengagernent of the various parts associated therewith inhibits any tendency toward rotative movement of the mandrel 15d. Hence, the collet 19a? and the valve 213 are substantially locked against rotation because of threaded interengagement of the valve 218 and the mandrel plus the connection of the mandrel 159 to the collet 190 via the anti-rotation pins 1% (FIG. 12). Therefore, removal of the adapter sleeve 23%; (FIG. 8), and the superposed running string of casing 296 which supports the sleeve, is readily accomplished by unthreading rotation of the casing and sleeve at the drilling barge.

If the well requires subsequent pulling of the production tubing string (FIGS. 13 and 14), the master valve 218 is closed by a diver. A string of casing such as the casing 296 (PEG. 19} is then run down over the flow line 228 with an unlatching tool 240 (FIGS. 13 and 14) threaded on its lower end. The unlatehing tool is provided with an internal threaded portion 242 which, when the tool and the casing string it depends from are rotated in the proper direction, is screwed onto the similar threads 224 on the valve 24 whereby the landing tool advances toward the collet 190. A beveled lower end portion 244 of the landing tool thus slides downward along the cumming surfaces Eli; of the collet fingers 208, and by the time an internal annular abutment 246 of the landing tool bottoms against the uppermost threads 224, the collet abutment ledges 212 are clear of the valve body collar 216 due to outward flexing of the collet fingers 208. An upward pull of the unlatching tool 240 (FIG. 14) thus lifts the mandrel 150 relative to the tubing hanger body 166 so that the lower portion of the collar 156 of the mandrel no longer restrains inward movement of the locking lugs 172. It is to be noted that the upper outer edge of the collar 216 is moved above the inner edges of the ledges 212 before the latter can move backv over the collar. Due to beveled upper edges at 248 of both the lugs 172 and the groove 34, when the mandrel collar 156 strikes the nut 170 and the tubing hanger body 166 moves upward, the lugs 172 are c ammed inward free of the mandrel 22 whereby the tubing string 155, the tubing hanger body 166, and all parts thereabove may be pulled to the drilling barge. The collet fingers of course return to their unstressed inner positions.

From the preceding description it is evident that the casing hanger and tubing hanger of the present invention provide efficient wellhead apparatus especially adapted for the underwater installation of casing and tubing strings from a drilling barge at the surface. The apparatus facilitates circulation of fluids without auxiliary apparatus or fixtures that are not a part of the permanent wellhead and also facilitates coupling and uncoupling of parts of the apparatus.

Method In carrying out the method of the present invention, the drilling barge B (FIG. 15) is anchored on location and a primary base unit 250 is run to the bottom over a drill string 252 after the borehole 124 is drilled. The primary base unit 250 includes suspension cables 254, a central upwardly and outwardly flared circular guide collar 256, and arms 257 projecting out from the collar and connected to the collar 255. Explosive bolts 259 (only one being shown in FIGURE 16) secure the primary base unit together until subsequent detonation of the bolts separates the primary base unit along a vertical plane which includes the center point of the guide collar 256.

The drilling string 252 and drill bit are then removed to the surface, and the primary base unit 250 remains on the bottom in alignment with the open borehole 124. A casing guide 260 (FIG. 16) is then slidably connected to the cables 254 at the drilling barge B, and the casing guide is clamped onto a guide shoe 262 that is aflixed to the lower end of the surface casing string 126. The casing guide 260 includes aligned arms 261 and 263 having semi-circular inner end portions which are secured together by shear bolts 266, and outer tubular portions 265 which are slidably mounted on the cables 254. The surface casing 126 is then run into the borehole and the casing guide 260 engages the guide collar 256 of the primary base unit 250 whereby the bolts 266 (FIG. 17) are sheared and the surface casing string 126 continues into the borehole 124-.

A wellhead assembly comprising the casing head 43 (FIGS. 2 and 17) and the drilling valve 130 is then made up at the drilling barge B on the landing joint of the surface casing 126. The drilling valve 130 is capable of remote hydraulic actuation from the drilling barge, as is the clamp 134 which secures the drilling valve to the casing head. The upper end of the drilling valve 139 is secured by a hydraulically actuated clamp 272 to the lower end of a ball joint 274. A main guide system 270 includes guide cables 276 and tubular guides 278 that are slidable on the cables and are anchored to lateral arms 280 projecting outward from the casing head 43. The arms 286 are separable along joints at 282, by explosive bolts, not illustrated, for the subsequent removal of the main guide system 270 from the casing head.

The primary base unit 250 (FIG. 17) is normally retrieved when the casing head 43 is in its FIGURE 18 position, such position being indicated by the casing head contacting the collar 256, and after cement at 122 is run into the bore hole exteriorly of the surface casing 126. When the explosive bolts 259 are detonated, the primary base unit separates along a center line plane and is then removed to the surface. In this manner the original guide cables 254 are removed, thereby leaving ample clearance for the main guide system 270. Although the primary base unit must be used to start the surface casing string 126 into the borehole and can be removed at the time suggested above, the unit can be removed any time after the casing string is in the borehole.

The cement at 122 in the annular space between the surface casing 126 and the borehole 124 is placed prior to installation of an assembly comprising the mandrel 22 (FIGS. 1 and 18), the sleeve valve 26 and the casing hanger 24, and before a lowermost borehole 286 is drilled. The drilling mud return path extends to the surface through the surface conductor 294 and through conventional blowout preventers, not shown, which are associated with the surface conductor at the drilling barge B. After drilling of the borehole 286 is completed, the casing hanger 24 and the mandrel 22 with its attached depending oil string 32 is installed in the well with an expansible packer 290 having a shear plug 292 on its lower end. The packer 290 is then expanded and the shear plug blown out, after which the oil string 32 is cemented in the borehole 286. The return paths for the drilling mud displaced during the cementing operation include the passages and ports 84 and 82 in the casing hanger 24, and the annular space between the surface conductor 294 and the running string 296. When the casing hanger 24 lands in the casing head 43, the locking lugs (FIG. 1) are automatic-ally projected into the groove 146 (FIG. 2) whereby the hanger is locked to the head.

If a storm should interrupt the drilling operations, the remotely operable drilling valve can be closed after the drill pipe is withdrawn from the hole. After releasing the hydraulically operated clamp 272 (FIG. 18) by remote control from the drilling barge B, the ball valve 274 and the superposed surface casing 294 are withdrawn to the surface. The guide cables 276 can then be attached to a floating buoy, not shown, thus allowing the barge B to move from the location. After the storm is over the barge can return to the location and the crew can pick up the buoyed guide cables and then run the surface conductor 294 and the ball valve 274 back down, and clamp the ball valve by the remotely operable clamp 272 to the drilling valve 130, whereby the drilling operation can proceed.

After the last described cementing operating, the running string of casing 296 (FIG. 18) above the casing hanger 24 is rotated at the surface. As previously mentioned in connection with FIGURES 2 and 3, such rotation disengages the landing tool 38 from the mandrel 22 and at the same time actuates the valve sleeve 26 whereby the circulation ports 82 and passages 84 are closed.

The production tubing string (FIGS. 8 and 19) is then made up to the tubing hanger 28 at the drilling barge B. The flexible flow line 228 is attached to the top end of the valve 218 and extends to the barge through the adapter 230 and the same running string of casing 296 which was used to land the mandrel 22. The upper end of the flexible flow line 288 (FIG. 21) is fitted with an end sub 362 which in turn carries a threaded adapter 394 having a valve removal plug 396 therein. After the tubing hanger 28 is landed, the casing string 2% and the adapter 230 are removed by rotating the casing to unscrew the adapter from the ball valve 218, and then pulling the adapter and casing to the surface over the flexible flow line 228. The hydraulically operated drilling valve 13% (broken away in FIG. 19), clamp 134, the surface conductor 294 and the guide system 276 are removed to the surface over the flexible flow line 228 after the arms 280 that interconnect the casing head 43 and the guide system 270 are separated moval tool 316. The valve 308 is then opened and the production fluid of the well, as shown at 312 (FIG. 23), is allowed to fiow through the open valve in order to clean up the well. After this last step, the valve 3% is closed and the flexible tubing is lowered to the bottom (FIG. 24) and is secured to a conventional flow line 314 by means of the valve 308. This connection is accomplished by a diver who then opens the valve 303 so that the production of flow of the well is transmitted through the flow line 3% to bulk storage or to distribution means ashore.

Features which are of special importance in the method, besides the capability of drilling and completing an underwater well without a diver, include the following: The well is under complete blowout prevention control at the drilling barge and can be temporarily abandoned at any time during the drilling operation and work can be resumed on the well without diving operations; and retrieval of the drilling valve and associated structure over the flexible ilow line assures well control at the drilling barge up to the time the well is completed.

Having thus described the invention, that which is believed to be new and for which protection by Letters Patent is desired is:

1. A valved casing hanger comprising an annular casing o hanger body having an axial bore theretnrough and a passage extending upwardly through the wall of the body and thence outwardly and terminating at the peripheral surface of said body, a valve sleeve slidable and rotable on said casing hanger body between upper and lower positions, and means interconnecting said casing hanger body and said valve sleeve such that rotation of said sleeve with respect to said body moves said sleeve between said upper and lower positions respectively opening and closing said passage.

2. A valved casing hanger comprising an annular casing hanger body adapted to be installed in and supported by a submerged casing head, said body having a passage in the wall of said casing hanger body, said passage extending upwardly through the wall of the body and laterally to a port at the peripheral surface of said body intermediate the upper and lower ends thereof, a sleeve valve circumscribing said casing hanger body and slidably and rotatably fitted thereon, said sleeve valve being movable between positions respectively opening and closing said port of said passage, and interconnecting means between said body and said sleeve valve to rotate said valve with respect to said body to open and close said port.

3. In a well apparatus, a pipe hanger body having a lateral port, a tubular valve member receiving said body therein and projecting generally coaxially upward from said body, a tool non-rotatably received in the upper end portion of the valve member, and means associated with said body and engaging said tool and valve member for causing opposite axial movement of said tool and member in response to rotation of said tool thereby to move said member between a closed position over said port and an open position exposing said port.

4. In a well apparatus, a tubular valve member having first and second end portions, a pipe hanger body extending into the first end portion of the valve member said hanger body having a port therein, an operating tool extending into the second end portion of the valve member, said tool and valve member having interengaging means precluding relative rotation between said tool and valve member, first means associated with said hanger body for releasably connecting said tool to the body and second means associated with said body and engaging said valve member for moving said valve member into a closed position over said port when said tool is disengaged from said first means and for moving said valve member into an open position displaced from said port when said tool is engaged with said first means.

5. The apparatus of claim 4 wherein said first means is a tubular member screw-threadably connected to said tool.

6. The apparatus of claim 4 wherein said second means includes screw-threads connected to said valve member.

'7. The apparatus of claim 4 wherein said first and second means include opposite handed screw-threads respectively screw-threadably connected to said tool and said valve member.

2%. A valved casing hanger assembly comprising an annular casing hanger body adapted to be installed in and supported by a submerged casing head, said body having a passage extending longitudinally through the wall of said body, said passage having upper and lower termini respectively located at the peripheral surface of said hanger body intermediate theends thereof and at the end surface of said hanger body, a valve sleeve slidably mounted on said hanger body for movement between positions closing and opening said upper terminus of the passage, a tubular mandrel extending axially through said hanger body in sliding contact with the inner surface of said body, stop means interconnecting said mandrel and said hanger body for limiting sliding movement of said mandrel relative to said hanger body between raised and lowered positions, and stop means carried by said mandrel and engageable with said sleeve valve for holding said valve in open position when said mandrel is in said raised position and for limiting downward sliding movement of said sleeve valve when said mandrel is in said lowered position.

9. In a well installation, a casing head; a casing hanger assembly including a tubular mandrel, a tubular casing hanger body slidably mounted on said mandrel and seated in said casing head, said body having a flow passage therein terminating in a lateral port, abutment means on said mandrel for limiting relative axial movement between said hanger body and said mandrel, interengaging means on said hanger body and said mandrel for preventing relative rotation between the body and the mandrel, said mandrel having internal screw-threads; and a landing tool having external screw-threads engaging the screw-threads on the mandrel for lowering the casing hanger body into said seated position in said casing head, the mandrel sliding downward in the hanger body by gravity when the body is seated in the casing head, said assembly also including a sleeve, and means mounting said sleeve on said hanger body for movement into a position over said port upon unthreading of the landing tool from the mandrel.

it). The combination of a tubular member having a screw-thread formed therein, a pipe hanger body mounted on said member, a landing tool having screw-threads engaged with the corresponding threads of the member, the wall of said hanger body having a passage therethrough, said passage having a port intermediate the upper and lower ends of said body which port terminates at the exterior surface of the body, a valve sleeve having an internal threaded portion and a lower end portion which end portion is slidably engaged with the exterior surface of said body, said sleeve being capable of being positioned with its lower end above said port, an externally threaded annular element secured on said pipe hanger body and threadedly engaged with the internal threads of said sleeve, the threads between said tool and member being of the opposite hand from the threads between said sleeve and said element, and means preventing relative rotation between said sleeve and said landing tool.

11. The combination of a tubular mandrel having a screw-thread formed therein, a tubular casing hanger body mounted on said mandrel, a landing tool having screw-threads engaged with the corresponding threads of the mandrel, the wall of said casing hanger body having a circulation passage extending longitudinally from its lower end surface to a lateral port intermediate the upper 13 and lower ends of said body which port terminates at the exterior surface of the body, a valve sleeve having an internal threaded portion and a smooth bore portion which bore portion is slidably engaged with the exterior surface of said hanger body, said sleeve being capable of being positioned with its lower end above said port, an externally threaded nut secured on the upper end portion of said casing hanger body and threadedly engaged with the internal threads of said sleeve, the threads between said tool and mandrel being of the opposite hand from the threads between said sleeve and nut, and means preventing relative rotation between said sleeve and said landing tool, whereby rotation of said landing tool simultaneously rotates and screws the sleeve over the nut in a direction to position the lower end portion of the sleeve in fluid sealing relation over said port and unscrews the landing tool from the mandrel, the respective threaded portions being so dimensioned that the landing tool is UNITED STATES PATENTS 1,863,890 6/1932 Wigle 166-89 2,080,610 5/1937 Humason 166-87 2,531,942 11/1950 Lee 251-343 2,631,000 3/1953 Lee 251-343 2,766,830 10/1956 Church 166-88 X 2,889,886 6/1959 Gould 166-89 3,171,674 3/1965 Bickel et a1 166-87 X 3,273,646 9/1966 Walker 166-86 3,324,951 6/1967 Balmer et a1 166-89 X 3,335,799 8/1967 Miller 166-87 X CHARLES E. OCONNELL, Primary Examiner. R. E. FAVREAU, Assistant Examiner. 

